1. Field of the Invention
The present invention relates to a measurement object for use in a wind tunnel test that includes a measurement object main body and a pressure sensitive paint applied on a surface of the measurement object main body. A light source irradiating excitation light is illuminated on the pressure sensitive paint and excites the pressure sensitive paint to generate phosphorescence so that an intensity of phosphorescence that varies according to pressure on the surface of the measurement object main body can be measured to determine a pressure distribution on the surface of the measurement object main body.
2. Description of Related Art
When a pressure sensitive paint applied to the surface of an object is irradiated with an excitation light, the intensity of phosphorescence emitted from the pressure sensitive paint changes according to the amount of oxygen molecules impinging on the phosphorescence. More specifically, the phosphorescence emitted is dependent on the pressure of air coming into contact with the pressure sensitive paint. Based on this finding, Japanese Patent Application Laid-open No. 7-12661 discloses a technique for measuring a pressure distribution (flow rate distribution) by measuring the intensity of phosphorescence.
In addition, Japanese Patent Application Laid-open No. 2002-228524 also discloses a technique in which a pressure detection sheet includes a pressure sensitive paint layer, a surface transparent electrode, a light emitting layer, an insulating layer, a back electrode, a back protective layer, and an adhesive layer that is affixed to the surface of a detection object. An excitation light generated by energizing the light emitting layer is applied to the pressure sensitive paint layer to generate phosphorescence. The intensity of phosphorescence is measured to determine a pressure distribution (flow rate distribution) on the surface of the detection object.
However, in the arrangement disclosed in Japanese Patent Application Laid-open No. 7-12661, since the pressure sensitive paint applied to the surface of the object is irradiated with an excitation light from outside of the object, it is necessary to employ a plurality of light sources in order to irradiate the entire surface of the pressure sensitive paint with excitation light. This results not only in an increase in the size of the entire system but also in a problem that it is difficult to uniformly irradiate the entire surface of the pressure sensitive paint with excitation light so that measurement errors are easily generated.
In addition, in the arrangement disclosed in Japanese Patent Application Laid-open No. 2002-228524, creases are inevitably generated when the pressure detection sheet including multiple layers is affixed to the surface of the detection object having a three-dimensional curved surface. The creases disadvantageously affect the airflow on the surface of the detection object, and give unevenness to the irradiation of the excitation light to the pressure sensitive paint layer.